package com.dong.executor;

import java.math.BigDecimal;

/**
 * @Description: TODO
 * @Auther: dongwq
 * @Date: 2021/5/24 18:21
 * @company：CTTIC
 */
public class DistanceUtils {
    public static void main(String[] args) {
        Long lng1 = new BigDecimal("81.643935").multiply(new BigDecimal(1000000)).longValue();
        System.out.println(lng1);
        Long lat1 = new BigDecimal("43.162066").multiply(new BigDecimal(1000000)).longValue();
        System.out.println(lat1);
        Long lng2 = new BigDecimal("81.643966").multiply(new BigDecimal(1000000)).longValue();
        System.out.println(lng2);
        Long lat2 = new BigDecimal("43.162115").multiply(new BigDecimal(1000000)).longValue();
        System.out.println(lat2);


        System.out.println(getDistance(lng1,lat1,lng2,lat2));

    }


    // 地球平均半径
    private static final double EARTH_RADIUS = 6378137;

    // 把经纬度转为度（°）
    private static double rad(double d) {
        return d * Math.PI / 180.0;
    }

    /**
     * 根据两点间经纬度坐标（double值），计算两点间距离，单位为米
     *
     * @param lng1
     * @param lat1
     * @param lng2
     * @param lat2
     * @return
     */
    public static double getDistance(double lng1, double lat1, double lng2, double lat2) {

        double radLat1 = rad(lat1 / 1000000d);
        double radLat2 = rad(lat2 / 1000000d);
        double a = radLat1 - radLat2;
        double b = rad(lng1 / 1000000d) - rad(lng2 / 1000000d);
        double s = 2 * Math.asin(Math.sqrt(Math.pow(Math.sin(a / 2), 2) + Math.cos(radLat1) * Math.cos(radLat2) * Math.pow(Math.sin(b / 2), 2)));
        s = s * EARTH_RADIUS;
        s = Math.round(s * 10000) / 10000;
        return s;
    }

}